Aquatic Ecology

1. Unit 3 Aquatic Ecology

2. Biogeochemical cycles Law of conservation of mass - matter cannot be created or destroyed

3. Remember 5 systems working together

4. What Sustains Life on Earth? • Solar Energy • The cycling of matter • Gravity Figure 3-7

5. Gravity • Holds the atmosphere (gases) close to the surface of the earth. • Moves materials downward to contribute to the cycling of matter.

6. Biogeochemical(Nutrient) Cycles The movement of chemical matter between sources and reservoirs/sinks. • Hydrologic Cycle - H2O • Carbon Cycle - C • Nitrogen Cycle - N • Phosphorous Cycle - P • Sulfur Cycle - S

7. Nutrients • Decomposition breaks down organic matter & returns chemicals/nutrients to the soil. • Nutrients can be limiting factors • Micro and macro amounts

8. Biosphere depends on Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Sulfur cycle Heat in the environment Heat Heat Heat

9. Hydrologic Cycle • Draw the water cycle in your notebook. • Did you include ice, rivers, ocean, runoff, groundwater, aquifer? • Did you label Evaporation, condensation, precipitation, transpiration? • What are evapotranspiration, infiltration, and percolation?

10. The Water Cycle Video By the National Science Foundation

11. The Hydrologic (water) Cycle Figure 3-26

13. Human impact on the Water Cycle • Mark number dots on your water cycle, then make a legend to explain the examples of human impact on the water cycle. • Ex: clearing a forest of trees can reduce evapotranspiration

14. Human Impact on Water Cycle

15. Effects of Human Activities on Water Cycle • Withdrawing large amounts of freshwater for drinking, irrigation, and industry. • Building large water-diversion or collection facilities. • Urbanization, clearing land, eroding soils. • Polluting surface and underground waterways and sources of water. • Contributing to climate change.

16. Work with partners at lab tables to complete water row of biogeochemical handout.(extra resource: textbook pages 66/67)

17. Composition of dry air • 78% Nitrogen • 21% Oxygen • 0.93% Argon • 0.033% Carbon dioxide

18. Basic Carbon Cycle

19. Basic Steps of carbon cycle • Autotrophs absorb CO2 from the atmosphere to use during photosynthesis. • Heterotrophs consume autotrophs • Heterotrophs release CO2 into the air during respiration. • All living organisms release CO2 into the air when they die and are decomposed by fungi & bacteria

20. Carbon reservoirs (sinks) • In oceans • In biosphere (organic matter) • In rocks/lithosphere and fossil fuels, like coal and oil - burning releases CO2 into atm

21. Carbon Cycle

22. Effects of Human Activities on Carbon Cycle • CO2 create a warming blanket • humans add excess CO2 to the atm. through: • Burning fossil fuels. • Clearing vegetation faster than it is replaced. • Ocean Acidification Figure 3-28

23. Work with partners at lab tables to complete carbon row of biogeochemical handout.(extra resource: textbook pages 66/67)

24. 3.

25. Phosphorus Cycle

26. Phosphorus • P is found in rocks/dust/ocean sediments. • Important to organisms – DNA & ATP • Can be limiting factor • Phosphorus is found in fertilizers.

27. Human Impact of phosphorus • Excessive amounts in aquatic ecosystems (from fertilizers) can cause eutrophication of ponds

29. The Sulfur Cycle

30. Sulfur Cycle • Mostly a gaseous cycle w/natural sources. • Volcanoes, anaerobic decay, and sea spray • S is stored in rocks/minerals/deep ocean sediments. • Large concentrations in the atmosphere can lead to acid rain or climate change. • Human impact: Combustion of fossil fuels (coal burning power plants) – air pollution

31. Work with partners at lab tables to complete sulfur row of biogeochemical handout.(extra resource: textbook pages 69-73)

32. Basic Nitrogen Cycle Wastes Wastes

33. Nitrogen Cycle • Nitrogen (N2) makes up almost 78% of air but is unusable. • Living organisms need fixed nitrogen to produce amino acids & proteins. • Nitrogen fixation occurs through lightning in atmosphere & bacteria in soil.

34. Nitrogen Cycle Vocab • Nitrogen Fixation – N2 is converted to NH3 (ammonia)by lightning, or by bacteria in the roots of plants. • Assimilation - Plant roots absorb nitrogen ions for cellular use, consumers eat plants for nitrogen assimilation

35. Vocab continued • Ammonification – Decomposers convert the biological nitrogen into simpler compounds such as NH3(ammonia). • Nitrification– Bacteria convert ammonia into nitrite, then to nitrate. • Denitrification – Bacteria reduce soil nutrients and N is released back into the atmosphere as N2(gas)

36. More Detailed Nitrogen Cycle

38. Effects of Human Activities on the Nitrogen Cycle • Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined. Figure 3-30

39. Human Effects on the Nitrogen Cycle • Burning of fossil fuels releases N compounds which bond with O2 and make for NOx’s which add to air pollution. • Used in fertilizers which adds to more N in water resulting in eutrophication. • Large scale animal management can lead to excess N compounds in water adding to eutrophication.

41. Relation to Biomes and Biodiversity • Ecosystems are constantly changing in response to changing environmental conditions.

42. Work with partners at lab tables to complete nitrogen row of biogeochemical handout.(extra resource: textbook pages 69-71)